Because we made copies, we want to remove duplicate file.

1. We'll remove newlist2.txt:
del newlist2.txt <ENTER>

2. You can remove now all files by typing (Make sure you are in the right folder, there's no undo in the command line!):
del *.* <ENTER>

(or simply: del . <ENTER>)

3. Now remove the directory John (remember how to do that?).